1. Field of the Invention
The present invention relates generally to devices arranged and designed to support loads and more specifically to devices which facilitate the installation of subsea equipment.
2. Description of the Related Art
In the offshore oil and gas production industry, flowlines are commonly used to facilitate fluid communication from one piece of subsea equipment to another. Several different devices are known in the art, which can enable such connection; however, a commonly used subsea device is what is known as a jumper system. In a typical jumper system, two end connectors, having a flowline portion connected therebetween, are each fluidly coupled with a piece of subsea equipment. These pieces of subsea equipment include, but are not limited to Christmas trees, manifolds, processing equipment, and other flowline ends. As an example, the jumper system can be used to fluidly couple a flowline with a wellhead. The first jumper end connector is fluidly coupled to the end of the flowline and the second end connector can be fluidly coupled with the wellhead.
The installation of a subsea jumper system initially involves the vertical lowering of the jumper system's associated parts—namely, the jumper end connectors, flowline portion and other equipment, which may be utilized—to the seabed. The fluid coupling of the end connectors will depend to a large degree on the type of end connectors involved and the pieces of subsea equipment being fluidly coupled. Some end connectors are vertically stabbed or landed on the device, fluidly mating therewith, while others can be horizontally stabbed or connected. Some end connectors require help from divers, while others can be installed utilizing a remotely operated vehicle (ROV).
One recognized device used in the vertical lowering of a jumper system to the seabed is a spreader bar. For example, in U.S. Pat. No. 6,405,802, issued to Williams, a subsea flowline jumper handling apparatus is disclosed having cables or lines suspended from a spreader bar to support the flowline jumper. When loads such as this are vertically lowered to the seabed, a problem exists if and when a spreader bar line goes slack. If one or more of the support lines go slack, an unequal support of the load can occur, thereby causing excessive stress in the load. Such a problem is even further exacerbated if the load has an unequal weight distribution.